I like check-raising this hand for a number of reasons: I don’t want to give free cards to random overs, I have blockers to the hands that have me in really bad shape (63, 53, 43), and I can plausibly get action from any sort of Ax that thinks it has two overs and a gutshot but actually has just 5 outs against me. I certainly intended to call a turn shove, but when he didn’t shove, I was sure he was drawing. I check-snapped the river expecting to see Ax, but this works too.

“I certainly intended to call a turn shove, but when he didn’t shove, I was sure he was drawing. I check-snapped the river expecting to see Ax”.
Hm.It looks to me that you made your mind on flop about his Ax holding.
His actions on turn or river are not going to change your mind.
What confidence!
I was expecting to see 67.

It was actually his failure to shove the turn that convinced me he had exactly a draw. Before that, getting value from Ax was only part of my reason for check-raising. My equity is good enough to get it in on the turn, so I didn’t need to make up my mind about what exactly he had. I just needed to know that I wasn’t folding.

Thanks Andrew for you explanation.My comment was not about criticism but curiosity
You see I play HU against weaker opponents and lower stakes and in my games I have a comfort to chose much better equity spots to put my stack in danger.
Your comments show me that high stakes HU dynamics is about pushing your stack in “very marginal” spots.
The turn SB shove did not change your equity very much.You do not have fold equity anymore but
I see that turn shove by SB widen his range dramatically so your equity is OK to call it- Ax is not the very bottom of his range.
So the river check call are best moves.

My basic observation is still valid.
You made some early assessment on flop about your equity and the plan to execute.
His actions on turn or river are not going to change your plan to put stacks in danger.